Identification of biological samples

ABSTRACT

A method for coding and identification of biological samples for in vitro fertilization comprises the steps of applying to receptacles intended for unfertilized eggs and sperm, respectively, an identification code characteristic of the patient; placing unfertilized eggs and sperm, respectively, in the receptacles; storing, transporting and admixing the respective samples in receptacles which each carry the same code; and implanting the resulting embryo in the patient. The identification code may based on RFID technology, in which sample vessels ( 12 ) are codified by the application of an RFID tag ( 13 ).

The present application is a divisional of and claims priority fromco-pending U.S. patent application Ser. No. 11/597,532, filed 24 Nov.2006 for “IDENTIFICATION OF BIOLOGICAL SAMPLES”.

This invention relates to the identification of biological samples foruse in in vitro fertilisation processes.

In vitro fertilisation is a process which is intended to enable a woman,apparently unable to conceive naturally, to gestate and give birth byimplantation, in the womb, of an externally-fertilised egg. During theprocess, unfertilised eggs are collected from the patient's ovaries andadmixed with sperm from the woman's partner for fertilisation purposes,the fertilised egg then being re-implanted in the womb for gestation.Clearly, it is important for the procedure to be administered under arigorous and carefully-controlled protocol to ensure that the eggs arefertilised with sperm from the intended partner; various instances havebeen reported in the media concerning unintended and highly distressingerrors which become apparent following birth. To this end, the HumanFertilisation and Embryology Authority operates a so-called “locked inprocess”, in which the procedure is witnessed at every stage by a personadditional to the operative to ensure, as far as possible, that mistakessuch as have been made in the past are not repeated in the future. Theprocedure is consequently expensive to operate and administer and, inany event, the possibility of human error cannot entirely be eliminated.

It is an object of the present invention to provide a procedure andassociated apparatus which enables samples to be coded and identified,especially for use in in vitro fertilisation procedures, in a way whichfalls within the requirements of the regulatory authority, in the UKthis being the Human Fertilisation and Embryology Authority.

In one aspect, the invention provides a method for coding andidentification of biological samples for in vitro fertilisation, themethod comprising the steps of applying to receptacles intended forunfertilised eggs and sperm, respectively, an identification codecharacteristic of the patient; placing unfertilised eggs and sperm,respectively, in the receptacles; storing, transporting and admixing therespective samples in receptacles which each carry the same code; andimplanting the resulting embryo in the patient. Preferably, theidentification codes are computer-readable, for example via a bench topreader, and information relating to the vessels and the samples storedtherein is maintained in a database which tracks the vessels and samplesand can provide information concerning their location at any given time.

Preferably, the identification code is based on RFID technology, inwhich sample vessels are codified by the application of write-on orprintable adhesive labels having an RFID tag permanently attachedthereto or incorporated therein, identification being by means ofactivation by radiation in the form of radio frequency waves, the tagemitting identification signals which can be received by the reader andstored in the database. The RFID tag may alternatively be incorporatedin the sample vessel itself. In alternative embodiments, ID tagsutilising electromagnetic frequencies other than radio frequencies, suchas microwave frequencies, may be used. The database may be controlled bysoftware which includes an anti-collision protocol to discriminatebetween data received from a plurality of vessels having differentidentification codes attached thereto.

In another aspect, the invention provides apparatus for identificationof biological samples for in vitro fertilisation, the apparatuscomprising storage vessels associated with an identification code; andmeans to read the code and transmit information relating to the samplesto a database.

In this specification, the term “vessels” is intended to cover vesselsfor use at any stage of the overall in vitro fertilisation procedurebetween initial collection of the egg and sperm samples, storagethereof, admixing thereof for fertilisation purposes and transmission ofthe embryo to the patient for implantation. Also in this specification,the term “patient” is to be understood, as the context requires, asapplying either to the woman or to the male partner.

In operation of the process and as reassurance for the patient, thepatient can observe and verify that the initial samples are placed invessels which correctly identify the patient and that the embryo is alsothus identified.

The method of the invention is preferably carried out on a laboratorybench beneath which is located an antenna for transmission of activationradiation and receiving signals emitted by the RFID tag. It isnecessary, in order for the samples to remain viable, for the benchsurface to be heated to a controlled temperature, preferably in therange 37-42° C. When handling or manipulating samples using conventionaltechniques, bench surfaces are typically made from stainless steel andheating thereof is by means of pipes disposed under and spaced from thebenchtop and through which hot water is circulated, a heat-conductiveplate, typically of aluminium or an aluminium alloy, being providedbetween the pipes and the surface material to equilibrate thetemperature differences between the pipes and their surroundings andresult in a substantially uniform surface temperature. However, with themethod of the present invention, signals between the antenna and sampleswill not transmit through a metal benchtop, nor will they communicatewith an RFID tag in close proximity, typically 1 mm or less, to a metalsurface. It is therefore necessary to utilise an electricallynon-conducting material for the benchtop, but this militates against theuse of temperature control measures which rely on thermal conductionfrom beneath the surface.

The reading means comprises an antenna and a reader for reading RFIDtags. The antenna forms part of an electrical circuit that is configuredto optimise the reading of RFID tags on or over the surface. The circuitincludes a transformer for providing power to the antenna and also anadjustable capacitor and an adjustable resistor. The transformer isconfigured to minimise any impedance mismatch between the reader and theantenna to improve the prospect of an RFID tag being readable on or overthe entire surface. The adjustable capacitor is set to tune to resonancethe coupling between the antenna and the RFID tag over the surface. Theadjustable resistor is set to dampen the magnetic field that the antennaproduces over the surface so that RFID tags placed over the surface arenot “swamped”.

According to another aspect, the invention provides a work stationproviding a warmed surface for supporting biological samples andcomprising RFID tag reading means located beneath the surface forreading RFID tags on or over the surface, wherein the station isstructured such that warming of the surface is achieved withoutpreventing reading by the reading means of an RFID tag associated withan item placed on the surface.

In one embodiment, the work station comprises a work area defined by anelectrically-insulating or resistive plate beneath which in use islocated an antenna for transmitting electromagnetic signals to samplereceptacles placed on the work area and receiving identification signalstherefrom, in which the plate is thermally conducting from one face tothe other, the lower surface being in thermal contact with atemperature-controlled heating medium. The work area may be set in aworkbench which may be made or example from stainless steel, the workarea providing a discrete working zone for the antenna and manipulationoperations carried out on the upper surface.

The plate may comprise glass coated on its lower surface with anelectrically-conducting heating layer such as indium tin oxide as theheating medium. Alternatively, the plate may comprise upper and lowerplate elements defining a cavity between them for containing a liquidheating medium, for example water at a thermostatically-controlledtemperature. Preferably, the water is pumped and recirculated throughthe cavity at a sufficiently high flowrate to minimise the temperaturedrop across the work area; preferably also, the flow is laminar.

Embodiments of invention will now be described by way of example withreference to the accompanying drawings, of which:

FIG. 1 is a diagrammatic view of a work station utilising one form ofheating means; and

FIG. 2 is a diagrammatic view of another embodiment using another formof heating means.

With reference firstly to FIG. 1, the apparatus consists essentially ofa stainless steel workbench surface (10) having an insert defining awork area and consisting of a toughened glass plate (11). A petri dish(12) having an RFID tag (13) attached to the under surface thereof isplaced on the work station. The glass plate (11) carries a lower coatingor deposit (14) formed from indium tin oxide, the layer beingelectrically connected to a power supply to provide an even heatingcurrent. An antenna (16) is disposed below the work station andconnected to test equipment (17).

In use, the antenna coil transmits activation signals to the RED tag(13) which itself transmits identification signals back to the antenna,the signals being processed in the test equipment (17). The power supply(15) supplies energy to the indium tin oxide layer (14) for heatingpurposes; the heat generated is transmitted through the plate (11) tomaintain the upper surface of the plate at the desired temperature.

With reference to FIG. 2, the work station consists essentially of upperand lower Conan (Registered Trade Mark) plates (21, 22) set into aworkbench as shown in FIG. 1. The plates are spaced apart to define agap (23) through which temperature-controlled water is passed in laminarflow to maintain the upper surface of the work station at the desiredtemperature. The work station is provided with an antenna and testequipment as described and illustrated with reference to FIG. 1.

The invention claimed is:
 1. Apparatus for identification of biologicalsamples for in vitro fertilisation, the apparatus comprising storagevessels associated with an identification code, the identification codebeing based on RFID technology, sample vessels being codified by theapplication of an RFID tag; the apparatus comprising: a surface defininga work area; a reader to read the RFID tag; an antenna for transmissionof activation radiation and receiving signals emitted by the RFID tag,the antenna located below the surface; a resistor to dampen the magneticfield produced by said antenna sufficient to prevent the RFID tag beingswamped and still allow communication between the antenna and the RFIDtag; a transformer to provide power to the antenna, the transformerconfigured to minimise any impedance mismatch between the reader and theantenna; and an adjustable capacitor to tune to resonance the couplingbetween the antenna and the RFID tag over the surface of the laboratorybench.
 2. The apparatus as claimed in claim 1, wherein the surface isdefined by an electrically-insulating or resistive plate, the antennabeing located below the plate.
 3. The apparatus as claimed in claim 2,wherein the plate comprises glass coated on its lower surface with anelectrically-conducting heating layer.
 4. The apparatus as claimed inclaim 1, wherein the surface is set in a workbench, the work areaproviding a discrete working zone on the upper surface of the workbench.